An inkjet printing apparatus having an inkjet print head arranged on a moveable carriage is well known in the art. The carriage is configured to reciprocate in a scanning direction. While the carriage moves, the inkjet print head ejects droplets of ink to form a swath of image dots on a recording medium. After one or multiple passes of the carriage, depending on a print strategy, the carriage and the recording medium are moved relative to each other, i.e. the recording medium may be moved or the carriage may be moved, in a transport direction, which is substantially perpendicular to the scanning direction. A next swath may then be printed. The next swath may be adjacent to the earlier swath or may be (partly) overlapping, depending on the print strategy, as is also well known in the art.
The image dots have commonly a diameter of about 40 micron or smaller, which corresponds to an image resolution of about 600 dots per inch (dpi), or higher. In order to obtain a high image quality, the positioning of the dots should be considerably better than their diameter. So, the position of each dot should be accurate and may only deviate about 10 micron or less, in particular relative to each other. To position the image dots of a second swath accurately compared to the image dots of a first swath, the movement of the carriage should be accurate and reproducible. In the prior art, many solutions to accurately control a movement and position of the carriage relative to the recording medium are available. However, the need for high speed printing requires higher carriage speeds, while even more print heads are arranged on the carriage, thereby increasing the weight of the carriage. From a mechanical and control perspective, increasing weight and speed while maintaining accurate positioning puts high demand on the mechanical construction.
On the other hand, there is a need to reduce costs, such as the manufacturing costs, of the inkjet printing apparatus. Thus, it is desired to and it is an object of the present invention to provide for a low cost mechanical construction that is suited to allow for high speed printing.